When God and Caesar claim controlling jurisdiction over public policy in America, public servants who are Catholic can get caught between a religious rock and a public policy hard place. Sen. John F. Kerry, who is at the center of a controversy over whether Catholic politicians should be denied Communion if their political views contradict church teaching, finds himself there. But he's not the first. I know. I've been there, too.

In 1965, Lyndon Johnson became the first president to support birth control as a public policy; he considered family-planning services for the poor an essential part of his antipoverty program. As his top assistant for domestic affairs, though initially uncomfortable, I came to the conviction that I had an obligation to promote presidential policies, including family planning, so long as the government did not require anyone to adopt practices contrary to their religious beliefs.

Johnson's aggressive posture on birth control earned him a stinging rebuke from the Catholic bishops in 1966. LBJ, typically, wanted it both ways. He was, he told me, "not going to deny contraceptives to any poor person who wanted them," but he sent me "to make peace with the Catholic bishops, because before long they may be the only allies we have on Negro rights and the poverty program."

It was my first political negotiation with the Catholic hierarchy. I met several times with their Washington representative, the Rev. Francis Hurley. I reminded Father Hurley that LBJ was doing God's work -- trying to eliminate poverty, helping the elderly, promoting equal rights for minorities. "The bishops," I argued, "should not attack and wound a president who, on balance, is advancing so many of their causes." We crafted an uneasy truce: If the president used the term "population problem" (which also allowed for solutions such as increasing available food) rather than "birth control" or "population control," the bishops would stay silent. Johnson kept his part of the bargain. So did the bishops.

Those were the days when you could sit down with the bishops; they were sensitive to the separation of church and state in the wake of the cliffhanger election of the first Catholic president, John F. Kennedy. The bishops and the laity accepted the assertion of the Jesuit theologian Gustave Weigel, in his widely reported 1960 lecture at Catholic University, that "the Roman Catholic Church would not attempt to interfere in the political activities of a Catholic president, nor would a Catholic president be bound by Catholic morality in deciding public issues."

It is my personal experience as a White House aide in the Johnson administration and as a Cabinet secretary for President Jimmy Carter that leads me to hope that Catholic bishops will not play the Eucharist card to press Catholic politicians to toe the anti-abortion (or any other) church line. I would prefer it if Kerry (and the 48 Catholic members of Congress who warned, in a letter to Washington Cardinal Theodore E. McCarrick, that U.S. bishops risk reviving anti-Catholic bigotry if they deny Communion to politicians who support abortion rights) expressed opposition to federal funding of abortion and voted to ban partial-birth abortion. But having experienced the complications and compromises -- the need to choose the lesser of two evils and the importance of having Catholics in public life -- I believe that public figures who are Catholic are entitled to consult their own conscience to determine whether they are entitled to receive Communion. The Catholic tradition of leaving that decision to the individual Catholic and God applies to Catholics who have divorced, sinned or eaten food five minutes before Mass. It should apply to public officials.

As a citizen I consider it preposterous and wrong for the political parties to impose an abortion litmus test on eligibility for their party's presidential nomination: in support of abortion rights for Democrats, and opposed to them for Republicans. But that is no reason for the bishops to make the same mistake by imposing a similar litmus test for the right to receive Communion.

If some bishops play the Eucharist card on abortion, will not others feel free to play it on the death penalty, cloning, stem cell research or support for the Iraq war, which the pope and the bishops have condemned as an unjust, immoral adventure? Will Communion be denied just to those who vote in support of abortion rights in Congress? Or will it also be denied to a senator like Rick Santorum, the Pennsylvania Republican whose outspoken support helped bring Arlen Spector, who supports abortion rights, victory over the anti-abortion candidate for the Republican senate nomination in that state? Will it be denied to Catholic governors who refuse to use their leniency power to commute death sentences?

When I became secretary of health, education and welfare (HEW) in 1977, I repeatedly confronted the tension between my religious beliefs and public policy -- and the bishops repeatedly confronted me. My first baptism by episcopal fire came on the issue of whether Medicaid should fund abortions. As a consequence of Roe v. Wade, Medicaid was then financing some 300,000 abortions a year. President Jimmy Carter and I sought to prohibit such funding "unless the life of the mother would be endangered if the fetus were carried to term."

Over our objection, Congress enacted a law that also permitted Medicaid funding of abortions in cases of rape or incest "promptly reported." At that point, my choice was to enforce the law or, as some suggested, to resign. I was not about to retire to some Walden Pond or Vatican Hill. So I issued regulations giving women 60 days to report cases of rape or incest, recognizing that in those days most women did not report such horrendous incidents unless they thought they were pregnant. The Catholic hierarchy erupted. So did President Carter. Both wanted a much shorter period, the bishops because they thought it would curb abortions; Carter because he thought it would reduce the opportunity for fraud. I held firm, believing that I had fairly reflected congressional intent. The Congress agreed with me.

Next I discovered that HEW was financing 100,000 sterilizations a year under guidelines more permissive than the law justified. The bishops wanted a complete ban; they considered morally unacceptable any experimentation or action that threatened the sanctity of life, including sterilization. Again I honored my obligation to follow the law. I issued regulations banning funds for the sterilization of anyone under 21 (on the ground that no minor could give informed consent to an irreversible procedure that goes to the essence of the life process) and of inmates of correctional facilities, mental hospitals or other rehabilitative facilities. To reduce the chances of sterilization under duress, I also forbade soliciting consent from anyone in childbirth labor, under the influence of alcohol or drugs, or who was seeking an abortion.

Moments after the British scientists Robert Edwards and Patrick Steptoe electrified the world in 1978 by announcing the birth of a normal child following in vitro fertilization, I was asked for my reaction, since the Catholic bishops had come out strongly against the procedure and I was a Catholic secretary of HEW. As a public official and nonscientist, I said my mind was open on whether the government should fund such research, and I established a commission representing a wide spectrum of opinion (including the Jesuit moral theologian Richard McCormick) to advise me. The group concluded unanimously that HEW should support research into this procedure.

On the issue of whether to fund fetal research -- the prologue to the current stem cell controversy -- I found in one corner the Alan Guttmacher Institute, which favored unfettered research, and in the other Sargent and Eunice Shriver, who represented the opposing Roman Catholic viewpoint. I put the two sides in the same room, reminding Guttmacher of the serious questions of human dignity and morality and the Shrivers of the potential benefits of such research. I challenged them to recommend a policy and budget sensitive to these considerations and promised to fight for it. They did, we did, and the research began -- and the controversy persists to this day.

In philosophy courses at Holy Cross College, I was taught that murder, suicide and euthanasia were morally wrong. I learned that each individual had an obligation to take ordinary means to preserve his or her life, but as Father Joseph Sullivan's ethics text stipulated, "one is not obligated to take extraordinary means." As HEW secretary, I had to make the vexing distinction between ordinary and extraordinary means of extending or terminating life, as our scientists wrestled with the will of God and each day unveiled a new medical machine, miracle pharmaceutical or surgical procedure.

The moral theology of the Catholic Church was an invaluable compass for me, but balancing my Catholic convictions with my obligations as a public servant was a wrenching intellectual, spiritual and emotional experience. In our secular democracy these issues of life and death involve questions about the right of individual Americans to decide and the obligation of the federal government to finance their decisions. They come freighted with religious beliefs and moral conviction, often further complicated by a lack of scientific certainty.

The Second Vatican Council encourages Catholics to rely more on individual conscience. But not until I became secretary of HEW did I begin to appreciate the significance -- and limitations -- of my personal convictions in making public decisions in a pluralistic democracy. I had been immersed in the Catholic religion -- devout parents and relatives, 16 years of Catholic education -- but my faith had never been tested until I became HEW secretary. I went from the sidelines into the arena, from sitting in the pew at Mass on Sunday to living with my faith throughout the week.

I found no automatic answers in Christian theology and the teachings of the church (or in the Democratic Party's or the administration's positions or in the science of medicine) to the perplexing and controversial questions of public policy on abortion, sterilization, aging, in vitro fertilization, fetal research, extending or cutting off the final days of terminally ill patients, and recombinant DNA and cloning. I was grateful for my entire life experience, from the streets of Brooklyn and the Jesuit classrooms at Brooklyn Prep and Holy Cross to the West Wing of the White House and my years as a Washington lawyer. I brought it all to the decisions at HEW, and I needed every bit of it.

Determining appropriate public policy on these matters is too complex, morally as well as politically, in our pluralistic democracy to be resolved by a jerk -- or bend -- of the knee by public leaders, legislators and judges who are Catholic -- or by the Catholic bishops who seek to influence such policy.

Joseph A. Califano Jr. is president of the National Center on Addiction and Substance Abuse at Columbia University. He was secretary of health, education and welfare from 1977 to 1979 and is the author of a memoir, "Inside: A Public and Private Life" (PublicAffairs). This article is adapted from one published last week in America magazine.